ATL: TROPICAL LOW ex-FRED (ex-07L)

[ozonepete]

Also, upwelling is always an issue when a hurricane stalls, but if it loops, the broader the loop, the less cooler water is brought up from below by the upwelling. Also, once a tropical cyclone goes to a low cat 1 or a TS, it doesn't tap out very much heat from the OCH (Ocean Heat Content) below it. So once Fred is a low cat 1 or a TS, upwelling is not a significant issue.

[cycloneye]

WTNT32 KNHC 110237
TCPAT2
BULLETIN
HURRICANE FRED ADVISORY NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072009
1100 PM AST THU SEP 10 2009

...FRED WEAKENS AND SLOWS DOWN A LITTLE MORE...

AT 1100 PM AST...0300 UTC...THE CENTER OF HURRICANE FRED WAS LOCATED
NEAR LATITUDE 17.4 NORTH...LONGITUDE 35.1 WEST OR ABOUT 740 MILES...
1190 KM...WEST OF THE CAPE VERDE ISLANDS.

FRED IS MOVING TOWARD THE NORTH NEAR 3 MPH...6 KM/HR. FRED IS
EXPECTED TO DRIFT NORTHWARD OR NORTH-NORTHEASTWARD OVER THE NEXT 48
HOURS.

MAXIMUM SUSTAINED WINDS HAVE DECREASED TO NEAR 85 MPH...140
KM/HR...WITH HIGHER GUSTS. FRED IS A CATEGORY ONE HURRICANE ON THE
SAFFIR-SIMPSON HURRICANE SCALE. ADDITIONAL WEAKENING IS EXPECTED
OVER THE NEXT COUPLE OF DAYS...AND FRED SHOULD WEAKEN TO A TROPICAL
STORM ON FRIDAY.

HURRICANE FORCE WINDS EXTEND OUTWARD UP TO 30 MILES...45 KM...FROM
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 115
MILES...185 KM.

ESTIMATED MINIMUM CENTRAL PRESSURE IS 980 MB...28.94 INCHES.

...SUMMARY OF 1100 PM AST INFORMATION...
LOCATION...17.4N 35.1W
MAXIMUM SUSTAINED WINDS...85 MPH
PRESENT MOVEMENT...NORTH OR 350 DEGREES AT 3 MPH
MINIMUM CENTRAL PRESSURE...980 MB

THE NEXT ADVISORY WILL BE ISSUED BY THE NATIONAL HURRICANE CENTER AT
500 AM AST.

$$
FORECASTER BERG

WTNT42 KNHC 110240
TCDAT2
HURRICANE FRED DISCUSSION NUMBER 14
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072009
1100 PM AST THU SEP 10 2009

SOUTHWESTERLY SHEAR CONTINUES TO DISRUPT THE STRUCTURE OF FRED. A
COMPARISON OF THE 37- AND 85-GHZ CHANNEL IMAGERY FROM A 2212 UTC
TRMM PASS INDICATES THAT THE MID-LEVEL CENTER OF ROTATION IS
DISPLACED ABOUT 20-25 N MI NORTH OF THE LOW-LEVEL CENTER...AND THE
MID-LEVEL REMNANT EYEWALL IS COMPLETELY ERODED ON THE SOUTHERN
SIDE. THIS PATTERN HAS YIELDED DVORAK CURRENT INTENSITY ESTIMATES
OF 77 KT FROM BOTH TAFB AND SAB...SO THE INITIAL INTENSITY IS
DECREASED TO 75 KT FOR THIS ADVISORY. ALL OF THE INTENSITY GUIDANCE
GRADUALLY WEAKENS FRED DUE TO 20-30 KT OF SOUTHWESTERLY SHEAR AND
MARGINALLY WARM SEA SURFACE TEMPERATURES OVER THE NEXT 48 HOURS...
WITH EVEN STRONGER SHEAR AFTER THAT. THERE IS VERY LITTLE SPREAD IN
THE INTENSITY MODELS...AND THE NHC FORECAST CALLS FOR FRED TO
WEAKEN TO A TROPICAL STORM BY 24 HOURS AND ULTIMATELY A REMNANT LOW
BY DAY 4.

THE STEERING CURRENTS AROUND FRED ARE BEGINNING TO COLLAPSE AND THE
INITIAL MOTION IS ESTIMATED AT 350 DEGREES AT 3 KT. ONLY A SLOW
NORTH TO NORTH-NORTHEASTWARD DRIFT IS EXPECTED DURING THE NEXT 48
HOURS AS FRED TEMPORARILY RESPONDS TO A MID-LEVEL TROUGH TO ITS
NORTH. ONCE IT WEAKENS AND BECOMES A SHALLOWER SYSTEM...THE
CYCLONE IS EXPECTED TO TURN NORTHWESTWARD AND WEST-NORTHWESTWARD
WITH AN INCREASE IN FORWARD SPEED UNDER THE INFLUENCE OF THE
LOW-LEVEL SUBTROPICAL RIDGE. THE NEW OFFICIAL FORECAST IS SLIGHTLY
EAST OF THE PREVIOUS TRACK DURING THE FIRST 48 HOURS BUT DOES NOT
SHOW AS MUCH OF AN EASTWARD BEND AS THE TVCN MODEL CONSENSUS.
STILL...THE MOTION WILL BE SLOW...AND FRED COULD MEANDER A BIT
DURING THE FIRST COUPLE OF DAYS OF THE FORECAST PERIOD BEFORE
ACCELERATING NORTHWESTWARD AFTER 72 HOURS.

FORECAST POSITIONS AND MAX WINDS

INITIAL 11/0300Z 17.4N 35.1W 75 KT
12HR VT 11/1200Z 17.7N 35.0W 65 KT
24HR VT 12/0000Z 17.9N 34.9W 55 KT
36HR VT 12/1200Z 18.0N 34.8W 45 KT
48HR VT 13/0000Z 18.3N 34.7W 35 KT
72HR VT 14/0000Z 20.0N 36.5W 30 KT
96HR VT 15/0000Z 21.5N 41.0W 25 KT...REMNANT LOW
120HR VT 16/0000Z 23.0N 45.5W 20 KT...REMNANT LOW

$$
FORECASTER BERG

[CrazyC83]

http://cimss.ssec.wisc.edu/tropic/real- ... g8sht.html

If it can survive and break the TUTT, it has minimal shear at about 24N/45W.

[ozonepete]

http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8sht.html

If it can survive and break the TUTT, it has minimal shear at about 24N/45W.

Or if the TUTT starts to lift out, that shear to its west will drop considerably. The models have been awful at predicting how shear will change this year. But actually, they've never been very good at it consistently from year to year, as Derek has pointed out many times.

[ozonepete]

Reintensifying a little, because it's drifting east or southeast just enough to avoid the shear. Fred has some interesting moves left.

[attallaman]

What is "ACE"?

tia

Here is an explanation of what ACE means.


http://en.wikipedia.org/wiki/Accumulate ... ual_storms

Now that's getting a little bit too technical for those of us who are not METs but are still interested in where storms might go. When I signed into S2K tonight and noticed on their website's graphics that indication of Fred making a turn to the west I decided to come here to check that out. I've been primarily interested in the home brew area of interest in the SW GOM and not Fred.

[leanne_uk]

any news on what our fred is upto this morning? I am on the mobile and cant get sat pictures up from the last pic above he is still holding up thankfully

Oh i hate having limited access because i am out and about lol

[vegastar]

Doesn't look very good...

[cycloneye]

110848
TCDAT2
HURRICANE FRED DISCUSSION NUMBER 15
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072009
500 AM AST FRI SEP 11 2009

THERE HAS NOT BEEN ANY RECENT MICROWAVE IMAGERY OVER FRED...SO IT
HAS BEEN DIFFICULT TO DIAGNOSE ANY STRUCTURAL CHANGES. OVERALL...
CONVECTION REMAINS QUITE STRONG NEAR THE MID-LEVEL CENTER...WITH
DVORAK INTENSITY ESTIMATES HOLDING STEADY NEAR 77 KT. YET
SATELLITE IMAGERY SHOWS THAT THE CLOUD PATTERN IS BECOMING
ELONGATED FROM THE SOUTHWEST TO NORTHEAST...WITH EVEN SOME HINTS
THAT THE LOW-LEVEL CENTER IS WELL SOUTHWEST OF THE MID-LEVEL
CENTER. FOR NOW...THE INITIAL WIND SPEED IS HELD AT 75 KT...BUT
THAT ESTIMATE COULD BE A LITTLE HIGH. THE INTENSITY FORECAST
APPEARS STRAIGHTFORWARD WITH 20-30 KT OF SOUTHWESTERLY SHEAR LIKELY
CAUSING STEADY WEAKENING OVER THE NEXT 48 HOURS...WITH EVEN STRONGER
SHEAR THEREAFTER. ALTHOUGH SSTS ARE MARGINALLY WARM...THE EXPECTED
SLOW MOTION OF FRED SHOULD CAUSE UPWELLING OF COOLER WATERS AND
HELP TO DIMINISH CONVECTION NEAR THE CENTER. THE NHC FORECAST
CONTINUES THE TREND OF THE PREVIOUS FORECAST AND IS SIMILAR TO THE
SHIPS MODEL.

IT APPEARS THAT FRED HAS TURNED TOWARD THE NORTH OR 000/3.
LITTLE NET MOTION IS EXPECTED OVER THE NEXT DAY OR TWO WITH A
MID-LEVEL TROUGH TO ITS NORTHWEST PERHAPS NUDGING THE TROPICAL
CYCLONE A LITTLE NORTHEASTWARD. ONCE FRED WEAKENS INTO A
SHALLOWER SYSTEM...THE CYCLONE SHOULD TURN NORTHWESTWARD AND
WEST-NORTHWESTWARD WITH AN INCREASE IN FORWARD SPEED UNDER THE
INFLUENCE OF A REBUILDING SURFACE RIDGE. THE OFFICIAL FORECAST IS
CLOSE TO THE PREVIOUS ONE THROUGH 48 HR THEN IS SHIFTED TO THE WEST
AFTERWARDS...A LITTLE SOUTH OF THE MODEL CONSENSUS.


FORECAST POSITIONS AND MAX WINDS

INITIAL 11/0900Z 17.7N 35.1W 75 KT
12HR VT 11/1800Z 17.9N 35.0W 60 KT
24HR VT 12/0600Z 18.0N 34.8W 50 KT
36HR VT 12/1800Z 18.2N 34.6W 40 KT
48HR VT 13/0600Z 18.6N 34.7W 35 KT
72HR VT 14/0600Z 20.0N 37.5W 25 KT
96HR VT 15/0600Z 21.5N 42.0W 20 KT...REMNANT LOW
120HR VT 16/0600Z 22.5N 47.5W 20 KT...REMNANT LOW

$$
FORECASTER BLAKE

[knotimpaired]

What is "ACE"?

tia

viewtopic.php?f=61&t=95832

You may want to print it out for quick reference.

[cycloneye]

I am not saying anything about any threats to land,only pointing out that GFS takes what may be left of Fred close to 20N-60W.



http://moe.met.fsu.edu/cgi-bin/gfstc2.c ... =Animation

[Blown Away]

75 kts at 5am, that's a little generous IMO. I see significant weakening happening rate now. Fred is quickly becoming a shallower system and I would not be surprised to see Fred not make it above 20N before turning W or WSW.

http://www.ssd.noaa.gov/goes/east/tatl/loop-avn.html

[Dean4Storms]

I'll be amazed if Fred was to make it all the way across the Atlantic as anything more than a remnant low and not get picked up in the westerlies. If it weakens enough it could threaten land eventually so long as conditions improved along the way eventually.

[vegastar]

70kts, at 1500Z. The shear is really kicking in:

[gatorcane]

I've noticed several runs of the GFS keep wanting to move Fred all the way across the Atlantic towards the Bahamas eventually.

What an unbelievable story if it managed to stay together and get that far west:


That is Fred in 7 days in the Central Atlantic heading west:

[Blown Away]

Ridge going to send Fred or leftover Fred W or even WSW. I'm hoping Fred can keeps its low intact so we can watch him for at least the next week! With the ridge building I think Fred will move quickly across the Atlantic, instead of the painfully slow movers we have watch this season.

[ozonepete]

None of this really matters, it may go west for a while as a remnant low, but it's not coming within 1000 miles of land.

It matters to us We enjoy the speculation. And the models haven't done that well with Fred so far.

[gatorcane]

Here is the GFS 06Z at 288 hours, with Fred impacting South FL, albeit the model run has low resolution.

It would truly be the story of the season considering everybody has written Fred off as a fish system, only for it to beeline west and make landfall.

[Sanibel]

"And now we can watch the models bend Fred west"...






(Doesn't look like there will be much left of it)

[Sanibel]

You can see Fred has taken dry Atlantic air all the way around to his south which will weaken it.